This application is related to and claims priority from Japanese patent application No. 2001-380877, incorporated herein by reference.
1. Field of the Invention
The present invention relates to a sealing member to be attached along a periphery of a door or an opening portion which is closed and opened by the door and, more particularly, to such a sealing member which has a magnet.
2. Description of Related Art
In order to effect an improved seal around a periphery of a hinged door of a building, household electrical appliance or the like, a sealing member having a magnet is attached along the periphery of the door or a facing opening portion. Examples of such a sealing member are disclosed in publication of unexamined Japanese patent application No. Hei 3-82643, and U.S. Pat. No. 5,614,052. In these examples, a tubular space is formed in a tubular seal portion of the sealing member so as to extend in a longitudinal direction of the tubular seal portion. The tubular space is formed along a seal part of a seal wall of the tubular seal portion, which is to contact and press a facing member when the door is closed. A bar-shaped magnet is accommodated in the tubular space. The bar-shaped magnet is composed of rubber, synthetic resin or the like, to which a magnetic material such as ferrite is added, and has a square (generally, rectangular) cross-sectional shape.
These sealing members are required to have the following characteristics: (a) the bar-shaped magnet exerts a magnetic force enough to attract the facing member, and provides a continuous seal line between the sealing member and the facing member over an entire length of the sealing member; (b) the bar-shaped magnet is lightweight; and (c) upon attaching of the sealing member along a corner of the periphery of the door, for example, the bar-shaped magnet can bend readily in conformity with the configuration of the corner.
The conventional bar-shaped magnet having a square cross-sectional shape, however, has the following problem. The magnet contacts and presses the facing member via the seal wall in a flat surface thereof, and accordingly, the flat surface cannot closely contact the corner of the facing member, thereby generating an interruption of a sealing line between the sealing member and the facing member.
The weight of the square magnet can be reduced and the bending properties thereof can be improved by decreasing the size of the cross-section of the magnet. But, If the size of the magnet is decreased, the contacting area of the magnet against the facing member becomes small, whereby the magnetic attraction thereof becomes insufficient, and the interruption of the sealing line between the sealing member and the facing member is enlarged.
Accordingly, it is an object of the present invention to provide a sealing member having a magnet which is lightweight and capable of exerting a magnetic force to attract a facing member when the sealing member contacts the facing member.
It is another object of the present invention to provide a sealing member having a magnet which is readily bent when the sealing member is attached along a corner of a door or an opening portion, thereby effecting a continuous seal line between the door and the opening portion.
The sealing member having a magnet in accordance with the present invention includes a base portion, a tubular seal portion which expands from the base portion and is surrounded by a seal wall. The seal wall contacts the opening portion or the periphery of the door in a contacting part upon closing of the door. The sealing member further includes a bar-shaped magnet which is provided in the tubular seal portion so as to extend in a longitudinal direction thereof. The bar-shaped magnet contacts an inside surface of the contacting part of the seal wall. The width of the cross-section of the bar-shaped magnet gradually decreases from the side of the contacting part of the seal wall inwardly of the tubular seal portion.
With the present invention, as compared to the conventional square magnet having the contacting area approximately identical to that of the bar-shaped magnet of the present invention, the cross-sectional area of the magnet can be reduced with the magnetic attraction approximately identical to that of the conventional magnet maintained. Accordingly, the magnet can be made lightweight, and can be readily bent to conform to the corner.
It is preferable to form a contacting surface of the bar-shaped magnet, which contacts the inside surface of the contacting part of the seal wall, into an outwardly curving surface. With this arrangement, when the sealing member is attached along a corner of the door or the facing opening portion, any interruption of a seal line between the sealing member and the facing surface can be prevented.
It is preferable to reduce the thickness of the contacting part of the seal wall, which the magnet contacts, as compared to a remaining part of the seal wall. With this arrangement, the magnetic attraction of the bar-shaped magnet against the facing member can be enhanced.
It is preferable to form a narrow part in about a middle of the tubular seal portion in the height direction thereof, and to provide the bar-shaped magnet in an upper half of the tubular seal portion above the narrow part while providing a plurality of sponge members in the tubular seal portion so as to extend in a longitudinal direction thereof in contact with an inside surface of the seal wall of the tubular seal portion.
With this arrangement, by virtue of the narrow part of the tubular seal portion, the upper half thereof, in which the bar-shaped magnet is provided, can tilt in such a direction as to exert a magnetic attraction on the facing member most strongly. In addition, by virtue of the sponge members provided in the tubular seal portion, undesirable deformation of the upper half of the tubular seal portion can be restrained upon attaching of the sealing member along the corner of the door or the facing opening portion, and the noise-insulating properties and sound-absorbing properties of the sealing member can be improved.
Other objects, features, and characteristics of the present invention will become apparent upon consideration of the following description and the appended claims with reference to the accompanying drawings, all of which form a part of this specification.